Incomplete information is a necessary condition for any real effects produced by monetary impulses. An alternative to the local-global inference problem is explored in this paper. Agents are confronted with permanent and transitory shocks. Even with full knowledge about the stochastic structure their best perception at any particular time will usually be erroneous Prices for each period are set at the beginning of the period on the basis of market conditions The realization of the shock process thus creates a short-run 'disequilibrium' absorbed by inventory adjustments. This adjustment translates perceived transitory monetary shocks into serially correlated output movements. The analysis proceeds within the context of rational expectations ...